1. Field of the Invention
The present invention relates to a technique for transmitting additional information using a digital broadcast system, and more particularly, to a technique for facilitating the embedding and transmission of additional information by eliminating a distortion that may occur in embedding the additional information into a digital broadcast signal.
2. Description of the Related Art
A digital watermark technology is a process of transmitting additional information using the same frequency band as that of a broadcast signal. A digital watermark technology aims to provide various additional data services.
Conventionally, a digital watermark technology is applied to a digital television (TV) broadcast signal during modulating the digital TV broadcast signal. However, modulation of a digital TV broadcast signal is processed in a digital broadcast exciter. Accordingly, to additionally embed a digital watermark signal into a digital TV broadcast signal, the digital broadcast exciter needs to be replaced.
The present invention provides an apparatus for embedding a digital watermark signal in the IF/RF type into an intermediate frequency/radio frequency (IF/RF) output signal of a digital broadcast exciter to eliminate the need to replace the existing digital broadcast exciter.